Climate Mitigation and the Phase-out of Ozone Depleting Chemicals

In addition to depleting the ozone layer, most ozone depleting substances controlled by the Montreal Protocol are also powerful greenhouse gases (GHGs). As such, activities under the Montreal Protocol have not only contributed to reversing the damage done to the ozone layer but also resulted in greenhouse gas reductions equivalent to several billion tonnes of CO2-equivalent, making the Montreal Protocol a key contributor to the global fight against climate change.

The phase-out of Ozone-Depleting Substances (ODS) under the Montreal Protocol has also supported the earth’s climate in another way. In the process of phasing-out ODS, manufacturers and industries upgrade equipment which results in fewer leaks of substitute chemicals to the atmosphere. Equipment upgrades also promote greater energy efficiency, thus reducing indirect emissions from energy generation.

However, it is essential to keep in mind these important co-benefits to climate change mitigation when implementing the Hydrochlorofluorocarbons (HCFCs) phase-out plans. HCFCs were considered critical in the smooth transition away from CFCs, but with the dramatic increase in the production and consumption of HCFCs over the past two decades, the threat from these chemicals to the ozone layer and climate change became more imminent since GWP of HCFCs is still significant (600-2,200 CO2-equivalent).

It is for these reasons that in 2007 the Parties to the Montreal Protocol took the decision to significantly accelerate the phase-out of HCFCs. Therefore, HCFC phase-out through the introduction of lower GWP alternatives can make significant contributions to climate change mitigation. Replacing HCFCs with the right alternatives in developing countries has the potential to reduce 14 – 18 billion tonnes of CO2-equivalent emissions over the next 20 – 30 years.

For more information on HCFC phase-out and the measures a country can take to ensure optimum climate mitigation benefits throughout HCFC phase-out, click here.

An additional threat to both the global climate and the ozone layer is posed by ODS that are contained in obsolete equipment (e.g. refrigerators replaced as part of energy efficiency programmes) or present in obsolete chemical stockpiles. These ODS threaten to leak into the atmosphere if they are not properly managed and disposed of, posing significant threats to both the ozone layer and the global climate. Because of these threats, the Parties to the Montreal Protocol instructed the Multilateral Fund (MLF) in 2007 to finance ODS bank destruction pilot projects in developing countries.

Combined, the destruction of ODS banks in developing countries has the potential to reduce 4 – 6 billon tonnes of CO2-equivalent emissions over the next 20 – 30 years.